The invention has for its object an extraction chamber for an automatic machine for the preparation of hot beverages.
Automatic machines using tablets or small pre-measured quantities with vertical introduction must receive or eject tablets that are sufficiently rigid that they do not stick and fall by gravity from the extraction chamber and this without using a complicated mechanical extractor. All these tablets or small quantities are either rigid or, if they are flexible, they comprise at least one rigid framework to facilitate their handling.
The state of the art can be defined by the following documents:
WO 95/07041: Espresso coffee maker characterized by the fact that the introduction of the tablet takes place in a vertical plane and the action of the piston is located in a horizontal plane and that the upper portion of said espresso coffee maker comprises a slot located in vertical alignment with and above abutments such that the positioning of the rigid member of each tablet or the like, between the abutments on the one hand and the boiler on the other hand, takes place by simple gravity. Each abutment is movable along an axis parallel to the longitudinal axis of the espresso coffee maker and an opening is provided in vertical alignment with and below the abutments such that when said abutments are manipulated so as to be parallel to each other, the tablet or the like is no longer retained by its rigid member and falls outside the espresso coffee maker by simple gravity.
WO 95/17121: Automatic machine for the preparation of infusions of hot beverages such as coffee, which comprises a group formed by a body placed facing a boiler, adapted to be brought together to form an infusion chamber, characterized by the fact that it comprises, between the body and the boiler, at the level of the infusion chamber:
reception means for an individual package containing the product to be infused, which are constituted by at least one retractable element extended in a substantially lower position adapted to immobilize temporarily said package between the body and the boiler,
means for holding the package in position which are constituted by two lateral substantially vertical grooves in which said package slides and is maintained in vertical position when the reception means are present, and
automatic ejection means for said package which are constituted by a retractable element which is retracted relative to the passage of the individual package to permit the ejection by simple gravity of the individual package, the movement of the individual package being perpendicular to the axis of the machine.
The invention permits, by means of this extraction chamber, using tablets or small pre-measured quantities formed of filter paper containing for example ground coffee, with or without a framework.
To this end, the extraction chamber, according to the invention, is of the type to supply tablets or small pre-measured quantities of ground coffee by vertical introduction, said extraction chamber is comprised of two portions movable in a horizontal plane, a movable portion or half-chamber is adapted for the inlet of hot water so as to be able to move toward or away from one another to close or open the extraction chamber with the vertical screen and the other vertical portion or half-chamber is provided with a vertical filter to receive and remove the coffee. The two portions movable in a horizontal plane are moreover mounted vertically oscillable one facing the other about their transverse axis. The two movable portions forming the extraction chamber are connected to each other to oscillate in reverse directions so as to open the chamber upwardly by forming a V to receive the supply, and to move together to close the extraction chamber during the extraction phase and finally to open the chamber downwardly by forming an inverted V, and this to permit the evacuation by gravity of the tablet or small quantity used.
In a preferred embodiment, the two movable portions each form vertically the volume of a half-chamber whose vertical bottom is movable to come, either flush with the vertical joint plane of the two portions, or, on the other hand, to retreat into the principal body of each portion to match all the volume of the half-chamber provided for this purpose in said principal body of each movable portion.
According to one embodiment, the bottom of the half-chamber is rigid but it is movably mounted on a means serving as a return spring which tends to unstick the rigid bottom of the principal body.
According to another embodiment, the bottom of the half-chamber is flexible, the central portion is rigid or semi-rigid and is held by a flexible peripheral membrane disposed at the inlet of each movable portion.
Each membrane is fixed on each movable portion by means such as a securement ring.
In other embodiments, the extraction chamber comprises guide means for the supply to position the supply substantially in a vertical position.
The lateral guide means for the supply can be adapted to hold it during the opening of each chamber to optimize non-sticking of the supply and the movable portions for the purpose of evacuation.
The guide means could comprise two vertical grooves adapted to coact with supply with a peripheral frame, said peripheral frame being inserted partially in the grooves.
The guide means could also form an abutment for at least one of the movable portions so as to limit its oscillatory movement.